Unity project exported to xCode: Build failed

I just exported my unity project to xCode and connected my iPad. But when i press play, the build fails. This error occur.

Command /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang failed with exit code 1

I never used xCode before, so it would be nice if it could be explained easy.

Check this answer: Problem building to an iOS device... - Questions & Answers - Unity Discussions

The most common issue behind for not being able to properly deploy an app to an iOS device is incorrect configuration of provisioning files, check to ensure you’ve properly provisioned your app and included your device on the specific provisioning profile you’ve created.

Have you created a provisioning profile for your app on the iOS provisioning portal and then double-checked you’ve got unity configured to use the correct one?